Go on, go over to the dark side. Everyone's doing it this Saturday, March 28, by turning off their lights for one hour, from 8:30pm to 9:30pm, to support the World Wildlife Fund’s Earth Hour. Hotels are joining the pro-earth gang too. Participants include London’s 12 Radisson Edwardian Hotels, hundreds of Starwood hotels spanning all of the chain’s brands (St. Regis, The Luxury Collection, W, Westin, Le Méridien, Sheraton, Four Points by Sheraton, Aloft, and Element), and scores of casino-hotels in Las Vegas, namely Harrah’s properties like Caesars Palace, the Flamingo, and Rio, among others. They’re also shutting off the Bellagio fountains, the volcano at the Mirage, and the Luxor beam. Last year, some 50 million switched off their lights for Earth Hour, as well as global landmarks like Rome’s coliseum and San Francisco’s Golden Gate Bridge. The target this year: 1 billion votes. Lights off equals a vote for earth, lights on, a vote for global warming. Which side are you on? We encourage all to spend an hour in the dark this Saturday to help combat climate change.